1 //===- ExprTypeConvert.cpp - Code to change an LLVM Expr Type ---------------=//
3 // This file implements the part of level raising that checks to see if it is
4 // possible to coerce an entire expression tree into a different type. If
5 // convertable, other routines from this file will do the conversion.
7 //===----------------------------------------------------------------------===//
9 #include "TransformInternals.h"
10 #include "llvm/iOther.h"
11 #include "llvm/iPHINode.h"
12 #include "llvm/iMemory.h"
13 #include "llvm/ConstantHandling.h"
14 #include "llvm/Transforms/Scalar/DCE.h"
15 #include "llvm/Analysis/Expressions.h"
16 #include "Support/STLExtras.h"
21 //#define DEBUG_EXPR_CONVERT 1
23 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
24 ValueTypeCache &ConvertedTypes);
26 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
29 // AllIndicesZero - Return true if all of the indices of the specified memory
30 // access instruction are zero, indicating an effectively nil offset to the
33 static bool AllIndicesZero(const MemAccessInst *MAI) {
34 for (User::const_op_iterator S = MAI->idx_begin(), E = MAI->idx_end();
36 if (!isa<Constant>(*S) || !cast<Constant>(*S)->isNullValue())
42 // Peephole Malloc instructions: we take a look at the use chain of the
43 // malloc instruction, and try to find out if the following conditions hold:
44 // 1. The malloc is of the form: 'malloc [sbyte], uint <constant>'
45 // 2. The only users of the malloc are cast & add instructions
46 // 3. Of the cast instructions, there is only one destination pointer type
47 // [RTy] where the size of the pointed to object is equal to the number
48 // of bytes allocated.
50 // If these conditions hold, we convert the malloc to allocate an [RTy]
51 // element. TODO: This comment is out of date WRT arrays
53 static bool MallocConvertableToType(MallocInst *MI, const Type *Ty,
54 ValueTypeCache &CTMap) {
55 if (!isa<PointerType>(Ty)) return false; // Malloc always returns pointers
57 // Deal with the type to allocate, not the pointer type...
58 Ty = cast<PointerType>(Ty)->getElementType();
59 if (!Ty->isSized()) return false; // Can only alloc something with a size
61 // Analyze the number of bytes allocated...
62 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
64 // Get information about the base datatype being allocated, before & after
65 int ReqTypeSize = TD.getTypeSize(Ty);
66 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
68 // Must have a scale or offset to analyze it...
69 if (!Expr.Offset && !Expr.Scale && OldTypeSize == 1) return false;
71 // Get the offset and scale of the allocation...
72 int OffsetVal = Expr.Offset ? getConstantValue(Expr.Offset) : 0;
73 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
75 // The old type might not be of unit size, take old size into consideration
77 int Offset = OffsetVal * OldTypeSize;
78 int Scale = ScaleVal * OldTypeSize;
80 // In order to be successful, both the scale and the offset must be a multiple
81 // of the requested data type's size.
83 if (Offset/ReqTypeSize*ReqTypeSize != Offset ||
84 Scale/ReqTypeSize*ReqTypeSize != Scale)
85 return false; // Nope.
90 static Instruction *ConvertMallocToType(MallocInst *MI, const Type *Ty,
91 const std::string &Name,
93 BasicBlock *BB = MI->getParent();
94 BasicBlock::iterator It = BB->end();
96 // Analyze the number of bytes allocated...
97 analysis::ExprType Expr = analysis::ClassifyExpression(MI->getArraySize());
99 const PointerType *AllocTy = cast<PointerType>(Ty);
100 const Type *ElType = AllocTy->getElementType();
102 unsigned DataSize = TD.getTypeSize(ElType);
103 unsigned OldTypeSize = TD.getTypeSize(MI->getType()->getElementType());
105 // Get the offset and scale coefficients that we are allocating...
106 int OffsetVal = (Expr.Offset ? getConstantValue(Expr.Offset) : 0);
107 int ScaleVal = Expr.Scale ? getConstantValue(Expr.Scale) : (Expr.Var ? 1 : 0);
109 // The old type might not be of unit size, take old size into consideration
111 unsigned Offset = (unsigned)OffsetVal * OldTypeSize / DataSize;
112 unsigned Scale = (unsigned)ScaleVal * OldTypeSize / DataSize;
114 // Locate the malloc instruction, because we may be inserting instructions
115 It = find(BB->getInstList().begin(), BB->getInstList().end(), MI);
117 // If we have a scale, apply it first...
119 // Expr.Var is not neccesarily unsigned right now, insert a cast now.
120 if (Expr.Var->getType() != Type::UIntTy) {
121 Instruction *CI = new CastInst(Expr.Var, Type::UIntTy);
122 if (Expr.Var->hasName()) CI->setName(Expr.Var->getName()+"-uint");
123 It = BB->getInstList().insert(It, CI)+1;
129 BinaryOperator::create(Instruction::Mul, Expr.Var,
130 ConstantUInt::get(Type::UIntTy, Scale));
131 if (Expr.Var->hasName()) ScI->setName(Expr.Var->getName()+"-scl");
132 It = BB->getInstList().insert(It, ScI)+1;
137 // If we are not scaling anything, just make the offset be the "var"...
138 Expr.Var = ConstantUInt::get(Type::UIntTy, Offset);
139 Offset = 0; Scale = 1;
142 // If we have an offset now, add it in...
144 assert(Expr.Var && "Var must be nonnull by now!");
147 BinaryOperator::create(Instruction::Add, Expr.Var,
148 ConstantUInt::get(Type::UIntTy, Offset));
149 if (Expr.Var->hasName()) AddI->setName(Expr.Var->getName()+"-off");
150 It = BB->getInstList().insert(It, AddI)+1;
154 Instruction *NewI = new MallocInst(AllocTy, Expr.Var, Name);
156 assert(AllocTy == Ty);
161 // ExpressionConvertableToType - Return true if it is possible
162 bool ExpressionConvertableToType(Value *V, const Type *Ty,
163 ValueTypeCache &CTMap) {
164 if (V->getType() == Ty) return true; // Expression already correct type!
166 // Expression type must be holdable in a register.
167 if (!Ty->isFirstClassType())
170 ValueTypeCache::iterator CTMI = CTMap.find(V);
171 if (CTMI != CTMap.end()) return CTMI->second == Ty;
175 Instruction *I = dyn_cast<Instruction>(V);
177 // It's not an instruction, check to see if it's a constant... all constants
178 // can be converted to an equivalent value (except pointers, they can't be
179 // const prop'd in general). We just ask the constant propogator to see if
180 // it can convert the value...
182 if (Constant *CPV = dyn_cast<Constant>(V))
183 if (ConstantFoldCastInstruction(CPV, Ty))
184 return true; // Don't worry about deallocating, it's a constant.
186 return false; // Otherwise, we can't convert!
189 switch (I->getOpcode()) {
190 case Instruction::Cast:
191 // We can convert the expr if the cast destination type is losslessly
192 // convertable to the requested type.
193 if (!Ty->isLosslesslyConvertableTo(I->getType())) return false;
195 // We also do not allow conversion of a cast that casts from a ptr to array
196 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
198 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
199 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
200 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
201 if (AT->getElementType() == DPT->getElementType())
206 case Instruction::Add:
207 case Instruction::Sub:
208 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap) ||
209 !ExpressionConvertableToType(I->getOperand(1), Ty, CTMap))
212 case Instruction::Shr:
213 if (Ty->isSigned() != V->getType()->isSigned()) return false;
215 case Instruction::Shl:
216 if (!ExpressionConvertableToType(I->getOperand(0), Ty, CTMap))
220 case Instruction::Load: {
221 LoadInst *LI = cast<LoadInst>(I);
222 if (LI->hasIndices() && !AllIndicesZero(LI)) {
223 // We can't convert a load expression if it has indices... unless they are
228 if (!ExpressionConvertableToType(LI->getPointerOperand(),
229 PointerType::get(Ty), CTMap))
233 case Instruction::PHINode: {
234 PHINode *PN = cast<PHINode>(I);
235 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
236 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
241 case Instruction::Malloc:
242 if (!MallocConvertableToType(cast<MallocInst>(I), Ty, CTMap))
247 case Instruction::GetElementPtr: {
248 // GetElementPtr's are directly convertable to a pointer type if they have
249 // a number of zeros at the end. Because removing these values does not
250 // change the logical offset of the GEP, it is okay and fair to remove them.
251 // This can change this:
252 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
253 // %t2 = cast %List * * %t1 to %List *
255 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
257 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
258 const PointerType *PTy = dyn_cast<PointerType>(Ty);
259 if (!PTy) return false; // GEP must always return a pointer...
260 const Type *PVTy = PTy->getElementType();
262 // Check to see if there are zero elements that we can remove from the
263 // index array. If there are, check to see if removing them causes us to
264 // get to the right type...
266 std::vector<Value*> Indices = GEP->copyIndices();
267 const Type *BaseType = GEP->getPointerOperand()->getType();
268 const Type *ElTy = 0;
270 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
271 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
273 ElTy = GetElementPtrInst::getIndexedType(BaseType, Indices, true);
275 break; // Found a match!!
279 if (ElTy) break; // Found a number of zeros we can strip off!
281 // Otherwise, we can convert a GEP from one form to the other iff the
282 // current gep is of the form 'getelementptr sbyte*, unsigned N
283 // and we could convert this to an appropriate GEP for the new type.
285 if (GEP->getNumOperands() == 2 &&
286 GEP->getOperand(1)->getType() == Type::UIntTy &&
287 GEP->getType() == PointerType::get(Type::SByteTy)) {
289 // Do not Check to see if our incoming pointer can be converted
290 // to be a ptr to an array of the right type... because in more cases than
291 // not, it is simply not analyzable because of pointer/array
292 // discrepencies. To fix this, we will insert a cast before the GEP.
295 // Check to see if 'N' is an expression that can be converted to
296 // the appropriate size... if so, allow it.
298 std::vector<Value*> Indices;
299 const Type *ElTy = ConvertableToGEP(PTy, I->getOperand(1), Indices);
301 if (!ExpressionConvertableToType(I->getOperand(0),
302 PointerType::get(ElTy), CTMap))
303 return false; // Can't continue, ExConToTy might have polluted set!
308 // Otherwise, it could be that we have something like this:
309 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
310 // and want to convert it into something like this:
311 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
313 if (GEP->getNumOperands() == 2 &&
314 GEP->getOperand(1)->getType() == Type::UIntTy &&
315 TD.getTypeSize(PTy->getElementType()) ==
316 TD.getTypeSize(GEP->getType()->getElementType())) {
317 const PointerType *NewSrcTy = PointerType::get(PVTy);
318 if (!ExpressionConvertableToType(I->getOperand(0), NewSrcTy, CTMap))
323 return false; // No match, maybe next time.
331 // Expressions are only convertable if all of the users of the expression can
332 // have this value converted. This makes use of the map to avoid infinite
335 for (Value::use_iterator It = I->use_begin(), E = I->use_end(); It != E; ++It)
336 if (!OperandConvertableToType(*It, I, Ty, CTMap))
343 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC) {
344 if (V->getType() == Ty) return V; // Already where we need to be?
346 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(V);
347 if (VMCI != VMC.ExprMap.end()) {
348 assert(VMCI->second->getType() == Ty);
350 if (Instruction *I = dyn_cast<Instruction>(V))
351 ValueHandle IHandle(VMC, I); // Remove I if it is unused now!
356 #ifdef DEBUG_EXPR_CONVERT
357 cerr << "CETT: " << (void*)V << " " << V;
360 Instruction *I = dyn_cast<Instruction>(V);
362 if (Constant *CPV = cast<Constant>(V)) {
363 // Constants are converted by constant folding the cast that is required.
364 // We assume here that all casts are implemented for constant prop.
365 Value *Result = ConstantFoldCastInstruction(CPV, Ty);
366 assert(Result && "ConstantFoldCastInstruction Failed!!!");
367 assert(Result->getType() == Ty && "Const prop of cast failed!");
369 // Add the instruction to the expression map
370 VMC.ExprMap[V] = Result;
375 BasicBlock *BB = I->getParent();
376 BasicBlock::InstListType &BIL = BB->getInstList();
377 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
378 Instruction *Res; // Result of conversion
380 ValueHandle IHandle(VMC, I); // Prevent I from being removed!
382 Constant *Dummy = Constant::getNullValue(Ty);
384 switch (I->getOpcode()) {
385 case Instruction::Cast:
386 Res = new CastInst(I->getOperand(0), Ty, Name);
389 case Instruction::Add:
390 case Instruction::Sub:
391 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
393 VMC.ExprMap[I] = Res; // Add node to expression eagerly
395 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
396 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), Ty, VMC));
399 case Instruction::Shl:
400 case Instruction::Shr:
401 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), Dummy,
402 I->getOperand(1), Name);
403 VMC.ExprMap[I] = Res;
404 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), Ty, VMC));
407 case Instruction::Load: {
408 LoadInst *LI = cast<LoadInst>(I);
409 assert(!LI->hasIndices() || AllIndicesZero(LI));
411 Res = new LoadInst(Constant::getNullValue(PointerType::get(Ty)), Name);
412 VMC.ExprMap[I] = Res;
413 Res->setOperand(0, ConvertExpressionToType(LI->getPointerOperand(),
414 PointerType::get(Ty), VMC));
415 assert(Res->getOperand(0)->getType() == PointerType::get(Ty));
416 assert(Ty == Res->getType());
417 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
421 case Instruction::PHINode: {
422 PHINode *OldPN = cast<PHINode>(I);
423 PHINode *NewPN = new PHINode(Ty, Name);
425 VMC.ExprMap[I] = NewPN; // Add node to expression eagerly
426 while (OldPN->getNumOperands()) {
427 BasicBlock *BB = OldPN->getIncomingBlock(0);
428 Value *OldVal = OldPN->getIncomingValue(0);
429 ValueHandle OldValHandle(VMC, OldVal);
430 OldPN->removeIncomingValue(BB);
431 Value *V = ConvertExpressionToType(OldVal, Ty, VMC);
432 NewPN->addIncoming(V, BB);
438 case Instruction::Malloc: {
439 Res = ConvertMallocToType(cast<MallocInst>(I), Ty, Name, VMC);
443 case Instruction::GetElementPtr: {
444 // GetElementPtr's are directly convertable to a pointer type if they have
445 // a number of zeros at the end. Because removing these values does not
446 // change the logical offset of the GEP, it is okay and fair to remove them.
447 // This can change this:
448 // %t1 = getelementptr %Hosp * %hosp, ubyte 4, ubyte 0 ; <%List **>
449 // %t2 = cast %List * * %t1 to %List *
451 // %t2 = getelementptr %Hosp * %hosp, ubyte 4 ; <%List *>
453 GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
455 // Check to see if there are zero elements that we can remove from the
456 // index array. If there are, check to see if removing them causes us to
457 // get to the right type...
459 std::vector<Value*> Indices = GEP->copyIndices();
460 const Type *BaseType = GEP->getPointerOperand()->getType();
461 const Type *PVTy = cast<PointerType>(Ty)->getElementType();
463 while (!Indices.empty() && isa<ConstantUInt>(Indices.back()) &&
464 cast<ConstantUInt>(Indices.back())->getValue() == 0) {
466 if (GetElementPtrInst::getIndexedType(BaseType, Indices, true) == PVTy) {
467 if (Indices.size() == 0) {
468 Res = new CastInst(GEP->getPointerOperand(), BaseType); // NOOP
470 Res = new GetElementPtrInst(GEP->getPointerOperand(), Indices, Name);
476 if (Res == 0 && GEP->getNumOperands() == 2 &&
477 GEP->getOperand(1)->getType() == Type::UIntTy &&
478 GEP->getType() == PointerType::get(Type::SByteTy)) {
480 // Otherwise, we can convert a GEP from one form to the other iff the
481 // current gep is of the form 'getelementptr [sbyte]*, unsigned N
482 // and we could convert this to an appropriate GEP for the new type.
484 const PointerType *NewSrcTy = PointerType::get(PVTy);
485 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
487 // Check to see if 'N' is an expression that can be converted to
488 // the appropriate size... if so, allow it.
490 std::vector<Value*> Indices;
491 const Type *ElTy = ConvertableToGEP(NewSrcTy, I->getOperand(1),
494 assert(ElTy == PVTy && "Internal error, setup wrong!");
495 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
497 VMC.ExprMap[I] = Res;
498 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
503 // Otherwise, it could be that we have something like this:
504 // getelementptr [[sbyte] *] * %reg115, uint %reg138 ; [sbyte]**
505 // and want to convert it into something like this:
506 // getelemenptr [[int] *] * %reg115, uint %reg138 ; [int]**
509 const PointerType *NewSrcTy = PointerType::get(PVTy);
510 Res = new GetElementPtrInst(Constant::getNullValue(NewSrcTy),
511 GEP->copyIndices(), Name);
512 VMC.ExprMap[I] = Res;
513 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0),
518 assert(Res && "Didn't find match!");
519 break; // No match, maybe next time.
523 assert(0 && "Expression convertable, but don't know how to convert?");
527 assert(Res->getType() == Ty && "Didn't convert expr to correct type!");
529 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
530 assert(It != BIL.end() && "Instruction not in own basic block??");
533 // Add the instruction to the expression map
534 VMC.ExprMap[I] = Res;
536 // Expressions are only convertable if all of the users of the expression can
537 // have this value converted. This makes use of the map to avoid infinite
540 unsigned NumUses = I->use_size();
541 for (unsigned It = 0; It < NumUses; ) {
542 unsigned OldSize = NumUses;
543 ConvertOperandToType(*(I->use_begin()+It), I, Res, VMC);
544 NumUses = I->use_size();
545 if (NumUses == OldSize) ++It;
548 #ifdef DEBUG_EXPR_CONVERT
549 cerr << "ExpIn: " << (void*)I << " " << I
550 << "ExpOut: " << (void*)Res << " " << Res;
553 if (I->use_empty()) {
554 #ifdef DEBUG_EXPR_CONVERT
555 cerr << "EXPR DELETING: " << (void*)I << " " << I;
558 VMC.OperandsMapped.erase(I);
559 VMC.ExprMap.erase(I);
568 // ValueConvertableToType - Return true if it is possible
569 bool ValueConvertableToType(Value *V, const Type *Ty,
570 ValueTypeCache &ConvertedTypes) {
571 ValueTypeCache::iterator I = ConvertedTypes.find(V);
572 if (I != ConvertedTypes.end()) return I->second == Ty;
573 ConvertedTypes[V] = Ty;
575 // It is safe to convert the specified value to the specified type IFF all of
576 // the uses of the value can be converted to accept the new typed value.
578 if (V->getType() != Ty) {
579 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I)
580 if (!OperandConvertableToType(*I, V, Ty, ConvertedTypes))
591 // OperandConvertableToType - Return true if it is possible to convert operand
592 // V of User (instruction) U to the specified type. This is true iff it is
593 // possible to change the specified instruction to accept this. CTMap is a map
594 // of converted types, so that circular definitions will see the future type of
595 // the expression, not the static current type.
597 static bool OperandConvertableToType(User *U, Value *V, const Type *Ty,
598 ValueTypeCache &CTMap) {
599 // if (V->getType() == Ty) return true; // Operand already the right type?
601 // Expression type must be holdable in a register.
602 if (!Ty->isFirstClassType())
605 Instruction *I = dyn_cast<Instruction>(U);
606 if (I == 0) return false; // We can't convert!
608 switch (I->getOpcode()) {
609 case Instruction::Cast:
610 assert(I->getOperand(0) == V);
611 // We can convert the expr if the cast destination type is losslessly
612 // convertable to the requested type.
613 // Also, do not change a cast that is a noop cast. For all intents and
614 // purposes it should be eliminated.
615 if (!Ty->isLosslesslyConvertableTo(I->getOperand(0)->getType()) ||
616 I->getType() == I->getOperand(0)->getType())
621 // We also do not allow conversion of a cast that casts from a ptr to array
622 // of X to a *X. For example: cast [4 x %List *] * %val to %List * *
624 if (PointerType *SPT = dyn_cast<PointerType>(I->getOperand(0)->getType()))
625 if (PointerType *DPT = dyn_cast<PointerType>(I->getType()))
626 if (ArrayType *AT = dyn_cast<ArrayType>(SPT->getElementType()))
627 if (AT->getElementType() == DPT->getElementType())
632 case Instruction::Add:
633 if (isa<PointerType>(Ty)) {
634 Value *IndexVal = I->getOperand(V == I->getOperand(0) ? 1 : 0);
635 std::vector<Value*> Indices;
636 if (const Type *ETy = ConvertableToGEP(Ty, IndexVal, Indices)) {
637 const Type *RetTy = PointerType::get(ETy);
639 // Only successful if we can convert this type to the required type
640 if (ValueConvertableToType(I, RetTy, CTMap)) {
644 // We have to return failure here because ValueConvertableToType could
645 // have polluted our map
650 case Instruction::Sub: {
651 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
652 return ValueConvertableToType(I, Ty, CTMap) &&
653 ExpressionConvertableToType(OtherOp, Ty, CTMap);
655 case Instruction::SetEQ:
656 case Instruction::SetNE: {
657 Value *OtherOp = I->getOperand((V == I->getOperand(0)) ? 1 : 0);
658 return ExpressionConvertableToType(OtherOp, Ty, CTMap);
660 case Instruction::Shr:
661 if (Ty->isSigned() != V->getType()->isSigned()) return false;
663 case Instruction::Shl:
664 assert(I->getOperand(0) == V);
665 return ValueConvertableToType(I, Ty, CTMap);
667 case Instruction::Free:
668 assert(I->getOperand(0) == V);
669 return isa<PointerType>(Ty); // Free can free any pointer type!
671 case Instruction::Load:
672 // Cannot convert the types of any subscripts...
673 if (I->getOperand(0) != V) return false;
675 if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
676 LoadInst *LI = cast<LoadInst>(I);
678 if (LI->hasIndices() && !AllIndicesZero(LI))
681 const Type *LoadedTy = PT->getElementType();
683 // They could be loading the first element of a composite type...
684 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
685 unsigned Offset = 0; // No offset, get first leaf.
686 std::vector<Value*> Indices; // Discarded...
687 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
688 assert(Offset == 0 && "Offset changed from zero???");
691 if (!LoadedTy->isFirstClassType())
694 if (TD.getTypeSize(LoadedTy) != TD.getTypeSize(LI->getType()))
697 return ValueConvertableToType(LI, LoadedTy, CTMap);
701 case Instruction::Store: {
702 StoreInst *SI = cast<StoreInst>(I);
703 if (SI->hasIndices()) return false;
705 if (V == I->getOperand(0)) {
706 ValueTypeCache::iterator CTMI = CTMap.find(I->getOperand(1));
707 if (CTMI != CTMap.end()) { // Operand #1 is in the table already?
708 // If so, check to see if it's Ty*, or, more importantly, if it is a
709 // pointer to a structure where the first element is a Ty... this code
710 // is neccesary because we might be trying to change the source and
711 // destination type of the store (they might be related) and the dest
712 // pointer type might be a pointer to structure. Below we allow pointer
713 // to structures where the 0th element is compatible with the value,
714 // now we have to support the symmetrical part of this.
716 const Type *ElTy = cast<PointerType>(CTMI->second)->getElementType();
718 // Already a pointer to what we want? Trivially accept...
719 if (ElTy == Ty) return true;
721 // Tricky case now, if the destination is a pointer to structure,
722 // obviously the source is not allowed to be a structure (cannot copy
723 // a whole structure at a time), so the level raiser must be trying to
724 // store into the first field. Check for this and allow it now:
726 if (StructType *SElTy = dyn_cast<StructType>(ElTy)) {
728 std::vector<Value*> Indices;
729 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
730 assert(Offset == 0 && "Offset changed!");
731 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
732 return false; // Can only happen for {}*
734 if (ElTy == Ty) // Looks like the 0th element of structure is
735 return true; // compatible! Accept now!
737 // Otherwise we know that we can't work, so just stop trying now.
742 // Can convert the store if we can convert the pointer operand to match
743 // the new value type...
744 return ExpressionConvertableToType(I->getOperand(1), PointerType::get(Ty),
746 } else if (const PointerType *PT = dyn_cast<PointerType>(Ty)) {
747 const Type *ElTy = PT->getElementType();
748 assert(V == I->getOperand(1));
750 if (isa<StructType>(ElTy)) {
751 // We can change the destination pointer if we can store our first
752 // argument into the first element of the structure...
755 std::vector<Value*> Indices;
756 ElTy = getStructOffsetType(ElTy, Offset, Indices, false);
757 assert(Offset == 0 && "Offset changed!");
758 if (ElTy == 0) // Element at offset zero in struct doesn't exist!
759 return false; // Can only happen for {}*
762 // Must move the same amount of data...
763 if (TD.getTypeSize(ElTy) != TD.getTypeSize(I->getOperand(0)->getType()))
766 // Can convert store if the incoming value is convertable...
767 return ExpressionConvertableToType(I->getOperand(0), ElTy, CTMap);
772 case Instruction::GetElementPtr:
773 if (V != I->getOperand(0) || !isa<PointerType>(Ty)) return false;
775 // If we have a two operand form of getelementptr, this is really little
776 // more than a simple addition. As with addition, check to see if the
777 // getelementptr instruction can be changed to index into the new type.
779 if (I->getNumOperands() == 2) {
780 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
781 unsigned DataSize = TD.getTypeSize(OldElTy);
782 Value *Index = I->getOperand(1);
783 Instruction *TempScale = 0;
785 // If the old data element is not unit sized, we have to create a scale
786 // instruction so that ConvertableToGEP will know the REAL amount we are
787 // indexing by. Note that this is never inserted into the instruction
788 // stream, so we have to delete it when we're done.
791 TempScale = BinaryOperator::create(Instruction::Mul, Index,
792 ConstantUInt::get(Type::UIntTy,
797 // Check to see if the second argument is an expression that can
798 // be converted to the appropriate size... if so, allow it.
800 std::vector<Value*> Indices;
801 const Type *ElTy = ConvertableToGEP(Ty, Index, Indices);
802 delete TempScale; // Free our temporary multiply if we made it
804 if (ElTy == 0) return false; // Cannot make conversion...
805 return ValueConvertableToType(I, PointerType::get(ElTy), CTMap);
809 case Instruction::PHINode: {
810 PHINode *PN = cast<PHINode>(I);
811 for (unsigned i = 0; i < PN->getNumIncomingValues(); ++i)
812 if (!ExpressionConvertableToType(PN->getIncomingValue(i), Ty, CTMap))
814 return ValueConvertableToType(PN, Ty, CTMap);
817 case Instruction::Call: {
818 User::op_iterator OI = find(I->op_begin(), I->op_end(), V);
819 assert (OI != I->op_end() && "Not using value!");
820 unsigned OpNum = OI - I->op_begin();
822 // Are we trying to change the function pointer value to a new type?
824 PointerType *PTy = dyn_cast<PointerType>(Ty);
825 if (PTy == 0) return false; // Can't convert to a non-pointer type...
826 FunctionType *MTy = dyn_cast<FunctionType>(PTy->getElementType());
827 if (MTy == 0) return false; // Can't convert to a non ptr to function...
829 // Perform sanity checks to make sure that new function type has the
830 // correct number of arguments...
832 unsigned NumArgs = I->getNumOperands()-1; // Don't include function ptr
834 // Cannot convert to a type that requires more fixed arguments than
835 // the call provides...
837 if (NumArgs < MTy->getParamTypes().size()) return false;
839 // Unless this is a vararg function type, we cannot provide more arguments
840 // than are desired...
842 if (!MTy->isVarArg() && NumArgs > MTy->getParamTypes().size())
845 // Okay, at this point, we know that the call and the function type match
846 // number of arguments. Now we see if we can convert the arguments
847 // themselves. Note that we do not require operands to be convertable,
848 // we can insert casts if they are convertible but not compatible. The
849 // reason for this is that we prefer to have resolved functions but casted
850 // arguments if possible.
852 const FunctionType::ParamTypes &PTs = MTy->getParamTypes();
853 for (unsigned i = 0, NA = PTs.size(); i < NA; ++i)
854 if (!PTs[i]->isLosslesslyConvertableTo(I->getOperand(i+1)->getType()))
855 return false; // Operands must have compatible types!
857 // Okay, at this point, we know that all of the arguments can be
858 // converted. We succeed if we can change the return type if
861 return ValueConvertableToType(I, MTy->getReturnType(), CTMap);
864 const PointerType *MPtr = cast<PointerType>(I->getOperand(0)->getType());
865 const FunctionType *MTy = cast<FunctionType>(MPtr->getElementType());
866 if (!MTy->isVarArg()) return false;
868 if ((OpNum-1) < MTy->getParamTypes().size())
869 return false; // It's not in the varargs section...
871 // If we get this far, we know the value is in the varargs section of the
872 // function! We can convert if we don't reinterpret the value...
874 return Ty->isLosslesslyConvertableTo(V->getType());
881 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC) {
882 ValueHandle VH(VMC, V);
884 unsigned NumUses = V->use_size();
885 for (unsigned It = 0; It < NumUses; ) {
886 unsigned OldSize = NumUses;
887 ConvertOperandToType(*(V->use_begin()+It), V, NewVal, VMC);
888 NumUses = V->use_size();
889 if (NumUses == OldSize) ++It;
895 static void ConvertOperandToType(User *U, Value *OldVal, Value *NewVal,
896 ValueMapCache &VMC) {
897 if (isa<ValueHandle>(U)) return; // Valuehandles don't let go of operands...
899 if (VMC.OperandsMapped.count(U)) return;
900 VMC.OperandsMapped.insert(U);
902 ValueMapCache::ExprMapTy::iterator VMCI = VMC.ExprMap.find(U);
903 if (VMCI != VMC.ExprMap.end())
907 Instruction *I = cast<Instruction>(U); // Only Instructions convertable
909 BasicBlock *BB = I->getParent();
910 BasicBlock::InstListType &BIL = BB->getInstList();
911 std::string Name = I->getName(); if (!Name.empty()) I->setName("");
912 Instruction *Res; // Result of conversion
914 //cerr << endl << endl << "Type:\t" << Ty << "\nInst: " << I << "BB Before: " << BB << endl;
916 // Prevent I from being removed...
917 ValueHandle IHandle(VMC, I);
919 const Type *NewTy = NewVal->getType();
920 Constant *Dummy = (NewTy != Type::VoidTy) ?
921 Constant::getNullValue(NewTy) : 0;
923 switch (I->getOpcode()) {
924 case Instruction::Cast:
925 assert(I->getOperand(0) == OldVal);
926 Res = new CastInst(NewVal, I->getType(), Name);
929 case Instruction::Add:
930 if (isa<PointerType>(NewTy)) {
931 Value *IndexVal = I->getOperand(OldVal == I->getOperand(0) ? 1 : 0);
932 std::vector<Value*> Indices;
933 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
935 if (const Type *ETy = ConvertableToGEP(NewTy, IndexVal, Indices, &It)) {
936 // If successful, convert the add to a GEP
937 //const Type *RetTy = PointerType::get(ETy);
938 // First operand is actually the given pointer...
939 Res = new GetElementPtrInst(NewVal, Indices, Name);
940 assert(cast<PointerType>(Res->getType())->getElementType() == ETy &&
941 "ConvertableToGEP broken!");
947 case Instruction::Sub:
948 case Instruction::SetEQ:
949 case Instruction::SetNE: {
950 Res = BinaryOperator::create(cast<BinaryOperator>(I)->getOpcode(),
952 VMC.ExprMap[I] = Res; // Add node to expression eagerly
954 unsigned OtherIdx = (OldVal == I->getOperand(0)) ? 1 : 0;
955 Value *OtherOp = I->getOperand(OtherIdx);
956 Value *NewOther = ConvertExpressionToType(OtherOp, NewTy, VMC);
958 Res->setOperand(OtherIdx, NewOther);
959 Res->setOperand(!OtherIdx, NewVal);
962 case Instruction::Shl:
963 case Instruction::Shr:
964 assert(I->getOperand(0) == OldVal);
965 Res = new ShiftInst(cast<ShiftInst>(I)->getOpcode(), NewVal,
966 I->getOperand(1), Name);
969 case Instruction::Free: // Free can free any pointer type!
970 assert(I->getOperand(0) == OldVal);
971 Res = new FreeInst(NewVal);
975 case Instruction::Load: {
976 assert(I->getOperand(0) == OldVal && isa<PointerType>(NewVal->getType()));
977 const Type *LoadedTy =
978 cast<PointerType>(NewVal->getType())->getElementType();
980 std::vector<Value*> Indices;
981 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
983 if (const CompositeType *CT = dyn_cast<CompositeType>(LoadedTy)) {
984 unsigned Offset = 0; // No offset, get first leaf.
985 LoadedTy = getStructOffsetType(CT, Offset, Indices, false);
987 assert(LoadedTy->isFirstClassType());
989 Res = new LoadInst(NewVal, Indices, Name);
990 assert(Res->getType()->isFirstClassType() && "Load of structure or array!");
994 case Instruction::Store: {
995 if (I->getOperand(0) == OldVal) { // Replace the source value
996 const PointerType *NewPT = PointerType::get(NewTy);
997 Res = new StoreInst(NewVal, Constant::getNullValue(NewPT));
998 VMC.ExprMap[I] = Res;
999 Res->setOperand(1, ConvertExpressionToType(I->getOperand(1), NewPT, VMC));
1000 } else { // Replace the source pointer
1001 const Type *ValTy = cast<PointerType>(NewTy)->getElementType();
1002 std::vector<Value*> Indices;
1004 if (isa<StructType>(ValTy)) {
1005 unsigned Offset = 0;
1006 Indices.push_back(ConstantUInt::get(Type::UIntTy, 0));
1007 ValTy = getStructOffsetType(ValTy, Offset, Indices, false);
1008 assert(Offset == 0 && ValTy);
1011 Res = new StoreInst(Constant::getNullValue(ValTy), NewVal, Indices);
1012 VMC.ExprMap[I] = Res;
1013 Res->setOperand(0, ConvertExpressionToType(I->getOperand(0), ValTy, VMC));
1019 case Instruction::GetElementPtr: {
1020 // Convert a one index getelementptr into just about anything that is
1023 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1024 const Type *OldElTy = cast<PointerType>(I->getType())->getElementType();
1025 unsigned DataSize = TD.getTypeSize(OldElTy);
1026 Value *Index = I->getOperand(1);
1028 if (DataSize != 1) {
1029 // Insert a multiply of the old element type is not a unit size...
1030 Index = BinaryOperator::create(Instruction::Mul, Index,
1031 ConstantUInt::get(Type::UIntTy, DataSize));
1032 It = BIL.insert(It, cast<Instruction>(Index))+1;
1035 // Perform the conversion now...
1037 std::vector<Value*> Indices;
1038 const Type *ElTy = ConvertableToGEP(NewVal->getType(), Index, Indices, &It);
1039 assert(ElTy != 0 && "GEP Conversion Failure!");
1040 Res = new GetElementPtrInst(NewVal, Indices, Name);
1041 assert(Res->getType() == PointerType::get(ElTy) &&
1042 "ConvertableToGet failed!");
1045 if (I->getType() == PointerType::get(Type::SByteTy)) {
1046 // Convert a getelementptr sbyte * %reg111, uint 16 freely back to
1047 // anything that is a pointer type...
1049 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1051 // Check to see if the second argument is an expression that can
1052 // be converted to the appropriate size... if so, allow it.
1054 std::vector<Value*> Indices;
1055 const Type *ElTy = ConvertableToGEP(NewVal->getType(), I->getOperand(1),
1057 assert(ElTy != 0 && "GEP Conversion Failure!");
1059 Res = new GetElementPtrInst(NewVal, Indices, Name);
1061 // Convert a getelementptr ulong * %reg123, uint %N
1062 // to getelementptr long * %reg123, uint %N
1063 // ... where the type must simply stay the same size...
1065 Res = new GetElementPtrInst(NewVal,
1066 cast<GetElementPtrInst>(I)->copyIndices(),
1072 case Instruction::PHINode: {
1073 PHINode *OldPN = cast<PHINode>(I);
1074 PHINode *NewPN = new PHINode(NewTy, Name);
1075 VMC.ExprMap[I] = NewPN;
1077 while (OldPN->getNumOperands()) {
1078 BasicBlock *BB = OldPN->getIncomingBlock(0);
1079 Value *OldVal = OldPN->getIncomingValue(0);
1080 OldPN->removeIncomingValue(BB);
1081 Value *V = ConvertExpressionToType(OldVal, NewTy, VMC);
1082 NewPN->addIncoming(V, BB);
1088 case Instruction::Call: {
1089 Value *Meth = I->getOperand(0);
1090 std::vector<Value*> Params(I->op_begin()+1, I->op_end());
1092 if (Meth == OldVal) { // Changing the function pointer?
1093 PointerType *NewPTy = cast<PointerType>(NewVal->getType());
1094 FunctionType *NewTy = cast<FunctionType>(NewPTy->getElementType());
1095 const FunctionType::ParamTypes &PTs = NewTy->getParamTypes();
1097 // Get an iterator to the call instruction so that we can insert casts for
1098 // operands if needbe. Note that we do not require operands to be
1099 // convertable, we can insert casts if they are convertible but not
1100 // compatible. The reason for this is that we prefer to have resolved
1101 // functions but casted arguments if possible.
1103 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1105 // Convert over all of the call operands to their new types... but only
1106 // convert over the part that is not in the vararg section of the call.
1108 for (unsigned i = 0; i < PTs.size(); ++i)
1109 if (Params[i]->getType() != PTs[i]) {
1110 // Create a cast to convert it to the right type, we know that this
1111 // is a lossless cast...
1113 Params[i] = new CastInst(Params[i], PTs[i], "call.resolve.cast");
1114 It = BIL.insert(It, cast<Instruction>(Params[i]))+1;
1116 Meth = NewVal; // Update call destination to new value
1118 } else { // Changing an argument, must be in vararg area
1119 std::vector<Value*>::iterator OI =
1120 find(Params.begin(), Params.end(), OldVal);
1121 assert (OI != Params.end() && "Not using value!");
1126 Res = new CallInst(Meth, Params, Name);
1130 assert(0 && "Expression convertable, but don't know how to convert?");
1134 // If the instruction was newly created, insert it into the instruction
1137 BasicBlock::iterator It = find(BIL.begin(), BIL.end(), I);
1138 assert(It != BIL.end() && "Instruction not in own basic block??");
1139 BIL.insert(It, Res); // Keep It pointing to old instruction
1141 #ifdef DEBUG_EXPR_CONVERT
1142 cerr << "COT CREATED: " << (void*)Res << " " << Res;
1143 cerr << "In: " << (void*)I << " " << I << "Out: " << (void*)Res << " " << Res;
1146 // Add the instruction to the expression map
1147 VMC.ExprMap[I] = Res;
1149 if (I->getType() != Res->getType())
1150 ConvertValueToNewType(I, Res, VMC);
1152 for (unsigned It = 0; It < I->use_size(); ) {
1153 User *Use = *(I->use_begin()+It);
1154 if (isa<ValueHandle>(Use)) // Don't remove ValueHandles!
1157 Use->replaceUsesOfWith(I, Res);
1160 if (I->use_empty()) {
1161 // Now we just need to remove the old instruction so we don't get infinite
1162 // loops. Note that we cannot use DCE because DCE won't remove a store
1163 // instruction, for example.
1165 #ifdef DEBUG_EXPR_CONVERT
1166 cerr << "DELETING: " << (void*)I << " " << I;
1169 VMC.OperandsMapped.erase(I);
1170 VMC.ExprMap.erase(I);
1173 for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
1175 assert(isa<ValueHandle>((Value*)*UI) &&"Uses of Instruction remain!!!");
1181 ValueHandle::ValueHandle(ValueMapCache &VMC, Value *V)
1182 : Instruction(Type::VoidTy, UserOp1, ""), Cache(VMC) {
1183 #ifdef DEBUG_EXPR_CONVERT
1184 //cerr << "VH AQUIRING: " << (void*)V << " " << V;
1186 Operands.push_back(Use(V, this));
1189 static void RecursiveDelete(ValueMapCache &Cache, Instruction *I) {
1190 if (!I || !I->use_empty()) return;
1192 assert(I->getParent() && "Inst not in basic block!");
1194 #ifdef DEBUG_EXPR_CONVERT
1195 //cerr << "VH DELETING: " << (void*)I << " " << I;
1198 for (User::op_iterator OI = I->op_begin(), OE = I->op_end();
1200 if (Instruction *U = dyn_cast<Instruction>(*OI)) {
1202 RecursiveDelete(Cache, U);
1205 I->getParent()->getInstList().remove(I);
1207 Cache.OperandsMapped.erase(I);
1208 Cache.ExprMap.erase(I);
1212 ValueHandle::~ValueHandle() {
1213 if (Operands[0]->use_size() == 1) {
1214 Value *V = Operands[0];
1215 Operands[0] = 0; // Drop use!
1217 // Now we just need to remove the old instruction so we don't get infinite
1218 // loops. Note that we cannot use DCE because DCE won't remove a store
1219 // instruction, for example.
1221 RecursiveDelete(Cache, dyn_cast<Instruction>(V));
1223 #ifdef DEBUG_EXPR_CONVERT
1224 //cerr << "VH RELEASING: " << (void*)Operands[0].get() << " " << Operands[0]->use_size() << " " << Operands[0];